From: "Gerd Möllmann" <gerd.moellmann@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: eller.helmut@gmail.com, emacs-devel@gnu.org
Subject: Re: MPS: Forwording symbols
Date: Mon, 17 Jun 2024 14:58:21 +0200 [thread overview]
Message-ID: <m2zfrjpvyq.fsf@pro2.fritz.box> (raw)
In-Reply-To: <86v827rc2x.fsf@gnu.org> (Eli Zaretskii's message of "Mon, 17 Jun 2024 15:24:54 +0300")
Eli Zaretskii <eliz@gnu.org> writes:
>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> Cc: eller.helmut@gmail.com, emacs-devel@gnu.org
>> Date: Mon, 17 Jun 2024 14:15:25 +0200
>>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>> >> > Hm, why do you think it writes to the data segment? Confusing names
>> >> > aside, it seems to read a value, which presumably is a pointer, adjusts
>> >> > it to the new basis and then writes it back.
>> >>
>> >> Becasue of this
>> >>
>> >> value += emacs_basis ();
>> >>
>> >> It has dumnped pointer - basis, and now uses that value to get the
>> >> pointer in the current process.
>> >
>> > Isn't this because the dumped data is loaded with a different base
>> > address than the one with which is was dumped?
>>
>> That'c correct. The same happens, with a different basis, for addresses
>> in the dump. Helmut asked how I know that it writes to Emacs' data
>> segment. That's from the use of emacs_basis.
>
> My reading of the code snippet you posted is that it writes to the
> same address as the one from which it read. IOW, the value is read,
> updated, and then written to the same address. Or what did I miss?
>
> Maybe I don't understand what you mean by "Emacs data segment" or what
> is the significance of that.
Oh, I think you're right, I landed in the wrong place. It seems to be
this one:
static void
dump_do_emacs_relocation (const uintptr_t dump_base,
const struct emacs_reloc reloc)
{
ptrdiff_t pval;
Lisp_Object lv;
switch (reloc.type)
{
case RELOC_EMACS_COPY_FROM_DUMP:
eassume (reloc.length > 0);
memcpy (emacs_ptr_at (reloc.emacs_offset),
dump_ptr (dump_base, reloc.u.dump_offset),
reloc.length);
break;
next prev parent reply other threads:[~2024-06-17 12:58 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-16 9:43 MPS: Forwording symbols Gerd Möllmann
2024-06-16 10:15 ` Gerd Möllmann
2024-06-16 19:27 ` Helmut Eller
2024-06-16 19:39 ` Gerd Möllmann
2024-06-17 10:57 ` Eli Zaretskii
2024-06-17 12:15 ` Gerd Möllmann
2024-06-17 12:24 ` Eli Zaretskii
2024-06-17 12:58 ` Gerd Möllmann [this message]
2024-06-17 3:43 ` Gerd Möllmann
2024-06-17 11:47 ` Eli Zaretskii
2024-06-17 18:10 ` Helmut Eller
2024-06-17 18:39 ` Gerd Möllmann
2024-06-17 18:50 ` Gerd Möllmann
2024-06-17 19:05 ` Helmut Eller
2024-06-17 19:19 ` Gerd Möllmann
2024-06-17 19:25 ` Helmut Eller
2024-06-17 20:07 ` Gerd Möllmann
2024-06-18 6:32 ` Gerd Möllmann
2024-06-18 9:05 ` Helmut Eller
2024-06-18 9:24 ` Gerd Möllmann
2024-06-18 10:44 ` Gerd Möllmann
2024-06-18 11:55 ` Helmut Eller
2024-06-18 12:21 ` Gerd Möllmann
2024-06-18 19:36 ` Helmut Eller
2024-06-18 19:55 ` Gerd Möllmann
2024-06-20 14:18 ` Helmut Eller
2024-06-20 15:16 ` Gerd Möllmann
2024-06-20 16:17 ` Helmut Eller
2024-06-20 16:27 ` Gerd Möllmann
2024-06-18 12:05 ` Helmut Eller
2024-06-18 12:29 ` Gerd Möllmann
2024-06-18 13:08 ` Eli Zaretskii
2024-06-18 12:36 ` Eli Zaretskii
2024-06-18 16:20 ` Helmut Eller
2024-06-18 16:29 ` Eli Zaretskii
2024-06-18 16:43 ` Gerd Möllmann
2024-06-18 16:37 ` Helmut Eller
2024-06-18 17:33 ` Eli Zaretskii
2024-06-18 17:51 ` Helmut Eller
2024-06-18 18:18 ` Eli Zaretskii
2024-06-18 17:54 ` Eli Zaretskii
2024-06-18 18:11 ` Gerd Möllmann
2024-06-18 18:20 ` Eli Zaretskii
2024-06-18 18:23 ` Gerd Möllmann
2024-06-18 18:12 ` Helmut Eller
2024-06-18 18:22 ` Eli Zaretskii
2024-06-18 19:27 ` Helmut Eller
2024-06-18 19:33 ` Gerd Möllmann
2024-06-19 11:22 ` Eli Zaretskii
2024-06-17 19:06 ` Gerd Möllmann
2024-06-21 15:36 ` Helmut Eller
2024-06-21 15:41 ` Gerd Möllmann
2024-06-21 16:20 ` Gerd Möllmann
2024-06-22 18:02 ` Helmut Eller
2024-06-22 18:27 ` Gerd Möllmann
2024-06-22 18:53 ` Helmut Eller
2024-06-22 19:26 ` Gerd Möllmann
2024-06-23 3:28 ` Gerd Möllmann
2024-06-23 4:10 ` Gerd Möllmann
2024-06-23 19:59 ` Helmut Eller
2024-06-24 3:45 ` Gerd Möllmann
2024-06-24 15:13 ` Helmut Eller
2024-06-24 16:14 ` Gerd Möllmann
2024-06-24 16:32 ` Eli Zaretskii
2024-06-24 17:00 ` Gerd Möllmann
2024-06-23 15:59 ` Helmut Eller
2024-06-23 16:26 ` Gerd Möllmann
2024-06-21 16:15 ` Ihor Radchenko
2024-06-21 16:25 ` Gerd Möllmann
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